Separable multiple tap connector



Filed July 8, 1955 l 4 6 6 VI \IQJ 0 a.

M %w 2 w L 1 mm, m 0 [H n W Z 0 u m u i 5 INVENTOR. /rw'r1 Mai/h ATTORN Y United States Patent 2,836,682 SEPARABLE MULTIPLE TAP CONNECTOR Irving F. Matthysse, Stamford, Conn., assignor to Burndy Engineering Co. Inc., a corporation of New York Application July 8, 1955, Serial No. 520,645 2 Claims. (Cl. 200133) My invention relates to a separable multiple tap connector and more particularly to a connector adapted to take current from a feeder cable and distribute it to various branches.

In mining operations, electrical power is distributed to the numerous mining machines by tapping from a main feeder. For this purpose a heavy metal junction box is used, within which the electrical connections are made. These boxes must be moved about as the mining operation progresses, but because of their weight and size, they are diflicult to move. In addition, they are costly, and connections and disconnections, which are made veryfrequently, are difficult to make.

It is an object of this invention to provide an air tight, lightweight, portable multiple tap connector whose enclosed taps may readily be connected and disconnected by hand.

It is a further object to provide each tap with a fuse which may be readily replaced when the tap is disconnected, and to provide such fuses with the proper time current clearing characteristics and interrupting capacity required for use with mining equipment.

Another object is to provide such a connector that is water-proof to operate in the moist and possibly flooded conditions in a mine. 8

Another object is to provide the device with all parts captured in such a manner that they cannot drop to the mine floor and become lost during the action of connecting, disconnecting or replacing fuses.

I accomplish these and other objects and obtain my new results as will be apparent from the device described in the following specification, particularly pointed out in the claims, and illustrated in the accompanying drawing in which:

Fig. 1 is an elevation of the connector forming my invention, shown in part and in partial section.

Fig. 2 is a bottom plan view of the entire connector.

Fig. 3 is an elevation of the same.

Fig. 4 is a plan view of a hexagonal internal contact spring.

The housing of my device consists of the aluminum alloy body and aluminum alloy cover 12 held together by the screws 14, and sealed by the sealing compound 16. Within the housing is the conducting bus bar 18 which distributes the electrical current to all the taps. Since the housing is made of metal for strength, the bus bar, which is supported on the housing, must be insulated from it. The bus bar is supported on the bosses 20 and fastened by the screws 22, While the insulating washers and bushings 24 and 26 insulate it from the housing and screws.

The conducting bus bar 18 has bosses 2S machined to provide for the electrical connections for the taps. The cylindrical openings 30 in these bosses receive the internal contact springs 32. The slot 34 is used to engage the spring detents 36 to lock the spring in place. Low electrical contact resistance is maintained to the contact 2,836,682 Patented May 27, 1958 plug 38 of the fuse 40, by means of the contact spring 32. Since the inside dimension across the flats of the hexagon shape of the contact spring is smaller than the diameter of the contact plug, the insertion of the plug tends to enlarge the contact spring. This enlargement is resisted bythe wall of the boss 28 resulting in high contact pressures where the spring contacts the wallet the boss and where it contacts the contact plug. The deflection of the flat sides 44 of the spring makes it possible to insert the plug, and their elasticity maintains the high contact force and low electrical resistance.

A similar means of maintaining low contact force is employed where the other contact plug 46 of the fuse engages the electrical tap connector 48. The tap conductor 50 is electrically and mechanically joined to connector 48 by tightening the set screws 52.

The retaining ring 54 located in the groove 56 of the tap housing 58 acts as a stop against which the tap connector 48 rests.

The tap housing 58 of the enclosure for the fuse 40 and tap connector 48 may be made of a strong insulation such as horn fibre. To provide strong threads for the metal nut 6b, the threaded metal insert 62 is force fitted into the counterbored end of the tap housing 58. The nut 60 is provided with an insulating cap 64 to protect against electrical contact with grounded metal.

The other end of the tap housing 58 is threaded to receive the aluminum alloy tap housing nut 68 which retains the rubber sealing washer 70 and the metal Washer 72. The tightening of this nut compresses the rubber Washer in the direction parallel to the centerline, thus causing it to expand in the radial direction and close down tightly on the tap cable insulation 74 and effect a seal. The rubber washer also seals against the tap housing 58, thus completing the seal at this end of the tap housing.

In a similar manner a seal is made where the tap housing 58 enters the body housing 10. The tightening of the nut '76 against the washer 78 compresses the sealing washer 88 causing it to grip and seal the tap housing 58 at seat 82 and seal against the body housing 10 at seat 84.

To assist in the alignment of the tap housing within the body housing, so that the fuse contact plug 38 will be fully engaged in the contact spring 32, the tap hous-' ing 58 has a groove 86 into which the washer falls when the parts are in alignment.

Electric current is fed into the device from the main cable 88. This cable must be large enough to supply the sum of the currents taken from each tap cable. However, no fuse is required at this end of the main cable, so that the main cable does not have to be readily detachable. It is joined to the conducting bus bar 18 through the connector 90 which is brazed to the conducting bus bar 18 at 92. Contact pressure is made to the main cable by means of the conducting wedge 94 which is forced in the longitudinal direction by the nut 96. This action causes the wedge to ride on the inclined surface 98, forcing it to exert transverse pressure on the main cable.

The connection for the main cable is protected from external contact and sealed by the main cable cover. 100.

The main cable cover separates from the body housing 10 by means of the cooperating threads at 102, thereby' sealed by the tightening of the nut 110 which compresses the sealing washer 112 through the metal washer 114. This compression causes the sealing washer to grip the main cableinsulation at seat 116, thereby making a seal. The pressure at the face 118 also seals to the main cover.

It is desirable that the main cable entrance be near the center of the entire assembly. This permits it to feed electric current in two directions along the conducting bus bar 18, so that no cross section-of the bus has to carry the entire main cable current. This permits a smaller cross-sectional area in the conducting bus bar than would be possible if the main cable entrance were at one end of the device.

To support the entire assembly from overhead or from a wall bracket, the U-bolt 120 is provided. The nuts 122 when tightened to fasten the U-bolt in place, compress the rubber Washer 124 between the frat washer 7.26 and the housing cover 12, thereby effecting a seal.

A boss 128 is provided on the housing body 1x; to which the ground wire 139 may be attached. The ground wire may be attached to any form of wire terminal 132 which is bolted to the boss 123 by means of screw 134, nut 136 and lockwasher 138.

The fuse 40 is shown in partial section in Fig. 1. 14% is a fusible wire surrounded by an arc quenching medium 142, such as gypsum or quartz sand. The fuses have accurate time-current characteristics to coordinate properly with other equipment. They have high short circuit interrupting capacity. The arcing when the fuse blows, is

rapidly extinguished. They are of rugged construction. 144 is a housing of strong insulating material such as horn fibre or laminated phenolic. An end cap 146 forms the closure of the housing at each end. 38 and 46 are the contact plugs which are brazed to the end caps. This I construction makes it possible to fill the housing with the arc quenching material before the second end cap is installed, after which the second end cap is installed and the fusible wire is soldered to it. The end caps are held rigidly to the housing by force fitting or spinning, which also seals the housing.

By using contact plugs 38 and 46 appreciably smaller in diameter than the end caps 146, the overall diameter of the tap housing 58 and the diameter of the outlet 152 on the body housing 10 may be kept to a minimum. This in turn permits the spacing between centers of the taps to be a minimum, making the overall length and width of the device a minimum. Thus, by this construction of the fuse, the entire assembly is made as small and light as possible.

To assemble a tap cable 50 to the connector 48, the combination of the metal nut 60 and its insulating cap 64 must be unscrewed from the tap housing 53. Then the fuse 40 (if one is already in place) and the connector 48 may be dropped out. Then the tap cable 59, with the insulation removed for a sufficient length, is pushed through the other end of the tap housing 58 (through the tap housing nut 68, Washer 72, sealing washer 70,

and retaining ring 54) and the bared end is inserted into the opening in the connector 48. By tightening the set screws 52, the tap conductor is securely gripped electrically and mechanically. The connector and tap cable are then pulled back through the tap housing until the connector rests against the retaining ring 54 and the nut 68 is tightened by hand until the bushing 7 0 securely grips ad seals to the tap cable insulation.

Fuse 40 is then inserted into the tap housing 58 until it shoulders against the connector 48, which assures that the contact plug 46 is fully engaged in the contact spring 32. The insulated cap 64 and nut 60 are then replaced to lock the fuse in place.

The fused tap assembly may then be connected to the conducting bus bar 18 by inserting it through the nut 76 which has been backed 'oflf suificiently to leave the sealing washer 80 uncompressed. When the tap assembly has been inserted all the way so that the contact plug 38 of the fuse fully engages the contact spring 32, the sealing washer 80 will fall into the groove 86 on the tap housing, thus holding the tap assembly in alignment. By hand tightening the nut 76, the sealing washer 80 will be made to grip and seal the tap assembly to the 'body housing.

The procedure for disconnecting the tap assembly or for replacing a blown fuse is obvious from the previous description.

It should be noted that any arcing that takes place due to breaking the tap cable circuit under load as the tap assembly is removed, is confined in the housing and would be extinguished before the end of the tap assembly is withdrawn from the sealing washer 80. This prevents the are from igniting any explosive gases in the vicinity.

I have thus described my invention, but I desire it understood that it is not confined to the particular forms or uses shown and described, the same being merely illustrative, and that the invention may be carried out in other Ways Without departing from the spirit of my invention, and, therefore, I claim broadly the right toemploy all equivalent instrumentalities coming within the scope of the appended claims, and by means of which, objects of my invention are attained and new results accomplished, as it is obvious that the particular embodiments herein shown and described are only some of the many that can be employed to attain these objects and accomplish these results.

-I claim:

1. A portable, multiple cable connector comprising a bus bar, a metal housing therefor, a cover for said housing, means for providing an insulated support between the bus bar and said housing, said bus bar provided with a plurality of connections for electrically securing the bared ends of insulated main and a plurality of feeder cables thereto, wherein a cable connection is provided with self-aligning contact spring to assure full electrical contact, said housing provided with a plurality of outlets for said cables, threaded sealing means for forming a readily attachable enclosure between said cables and said housing, and means for manually making an electrical disconnection of the feeder cables to the bus bar within the closed metal housing.

2. A portable, multiple cable connector comprising a bus bar, a metal housing therefor, a cover for said housing, means for providing an insulated support between the bus bar and said housing, said bus bar provided with a plurality of connections for electrically securing the bared ends of insulated main and a plurality of feeder cables thereto, wherein a cable connection includes a cylindrical fuse containing body having a fuse contact plug at each end thereof, having a diameter appreciably smaller than the fuse containing body, said housing provided with a plurailty of outlets for said cables, threaded sealing means for forming a readily attachable enclosure between said cables and said housing, and means for manually making an electrical disconnection of the feeder cables to the bus bar within the closed metal housing.

References Cited in the file of this patent UNITED STATES PATENTS 

